1 / 33

GD&T Harmonization Results Bath SC4 Meeting

GD&T Harmonization Results Bath SC4 Meeting. David Loffredo loffredo@steptools.com 2004-07-08 STEP Tools, Inc. 14 First Street, Troy, NY 12180 (518) 687-2848 / (518) 687-4420 fax. Progress During Week. Discussed and Resolved Incompatibilities

mikayla-maldonado
Download Presentation

GD&T Harmonization Results Bath SC4 Meeting

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. GD&T Harmonization ResultsBath SC4 Meeting David Loffredo loffredo@steptools.com 2004-07-08 STEP Tools, Inc. 14 First Street, Troy, NY 12180 (518) 687-2848 / (518) 687-4420 fax

  2. Progress During Week • Discussed and Resolved Incompatibilities • Handling of value qualifications (range, plus/minus, etc) • reviewing proposed change for value range, all other qualifications RESOLVED • Types of dimensions identified: RESOLVED • Mapping of envelope principle: RESOLVED • Directed angular location, determination of angle orientation • All models already harmonized. Continue to study ways to improve the ARM. Leave alone for now. • Discussed Big Picture Strategies for GD&T • Linking of dimensions with the draughting presentation elements of the dimensions. • Relationships with TC 10 and TC 213 • Developed response to TC-213 “expression of concern”

  3. Position Statement For TC-213 • In response to TC-213 “expression of concern”: • We are happy to use TC 213 terminology, and note that we are already referring to 5459:1981 for the definition of Datum. • We ask TC-213 to point out areas where we differ and we will be happy to adopt their terminology. • Already using the “Common_Datum” term as AIM entity defined in AIC 519 • Will change uses of “Compound Datum” term to “Common Datum.”

  4. Summary of Resolutions (1/2) • Value qualifications • Limitation, agreement to clarify mappings in AP-224 • Plus/minus, agreement on separate representations for use inside and outside of dimensions. AP-214 to correct mappings inside dimension to make proper use of dimensional_size, add new mapping for use outside of dimensions • Limits and fits, as with plus/minus • Value range, still in discussion. Willingness from AP-224 to use value_range outside of dimensions, and extend ARM to support ranges for normal properties. AP-214 unsure about using two rep item approach inside of dimensions. • Continue discussion on value range via email/conf call, once Max has had time to get additional input from his team.

  5. Summary of Resolutions (2/2) • Types of Size Dimensions • Update AP-214, AP-224, and Module 1050 as follows: • Expand list of specific size dimensions to the union of types in 224, 214 and those “hiding” under general_size. • Rename general_size to externally_defined_size and add a document reference that calls out where it is defined. • Upward compatible change to AP-214, 1050 • Envelope Principle • Update AP-214/Module 1050 AIM mappings to current AP-224 approach and will relax ARM to allow envelope on any size dimension. • Update AP-224 ARM to restrict usage of envelope to size only by moving attribute in the ARM to size_dimension

  6. General Approach During Week • Reviewed ARM and AIM issues. • Surveyed the room for technical and business priorities and constraints. • Considered each issue to find options consistent with above priorities.

  7. Goals • Rank the following technical priorities so that we can evaluate our options • Absolute minimal changes to existing standards • May make standards more complex with alternate mappings. Benefits current implementations. • Absolute minimal changes to existing implementations • Standard may become more complex than above, even more benefits to current implementations. Minimize or eliminate change visible to implementers. • Customers which would be disillusioned by any changes to the standard. • Simplicity of resulting specification • Consistent pattern so implementers know what to expect. Benefits adoption and future implementation. • Also may encourage use in other contexts • Minimize adoption time • Accurate use of Integrated Resource semantics

  8. Positions • Person (Perspective) -- Prioritization of values • A - Min Change to STD, B- Min Change to Impl., C- Simplicity, D - IR accuracy • Bill Freeman (customer rep), Len Slovensky (224, 240, 223) - B, A, D, C • Sean Barker - D + Speed • Vanessa Lees (CTC) - D • Alan Crawford (224, customer rep)- Customer Impact (B), Credibility of STEP, Reuse of Existing Base • Martin Gibson - Customer Impact (B), Credibility of STEP • Max Ungerer (214, customer rep) - B (tolerances not implemented, but value ranges are implemented in other areas of the standard), A, speed, C, D • Tom Hendrix (203e2/modules) - D + Speed • King Yee (203e2/parametrics) - D + Speed, B • Chiakai Sakamoto (240) - B, A, D, C • Hiroyuki Hiraoka - C, Expandability • Vijay Srinivasan (TC213) - none of the above (IBM/Dassault) D + Speed • Friedrich Glantschnig (14649) - As with Alan Crawford above, push back any changes to IRs • Suk-Hwan Suh (14649) - C + Speed • Martin Hardwick (tool vendor) - Maximum new implementation => D, C, Speed • Ted Vorburger (219) - B, A, and to lesser extent D, C

  9. Analysis • B very important, D very important, Speed important • A - Min Change to STD, B- Min Change to Impl., C- Simplicity, D - IR accuracy • AP-214 tolerances not implemented, but value ranges and limits are implemented in other areas of the standard • AP-224 tolerances implemented with all qualifications • Plus/Minus most common • range, limitation, limits and fits - how common? • AP-224 feature plus/minus widely used • use of limitation outside of dimension - how common? • does not support use of value range, limits and fits outside of dimensional tolerance

  10. Discussion Results • Value Limitation • Value Range • Plus/Minus • Limits and Fits • Set of Possible Size Dimensions • Envelope Principle • Angular Location Dimension

  11. Value Limitation Mapping This approach is defined in both AP-214 and AP-224 Dimension or property definition on something Name of Limit AP-214 specifies “maximum” or “minimum” AP-224 does not specify string, but uses “MAX” and “MIN” in an example Adds qualified representation item to the complex instance representation complex instance of measure_representation_item length_measure_with_unit qualified_representation_item name = “length” value = 100 mm type_qualifier name = “maximum” precision_qualifier precision_value = 4 Separate qualifier significant digits Numeric value for limit

  12. Value Limitation Resolution • AP-224 will clarify ARM by creating subtype of Tolerance_limit for: • Maximum limit -- mapping will call out name=“maximum” • Minimum limit -- mapping will call out name=“minimum” • Other limit - mapping will leave name unconstrained.

  13. Value Range • AP-224 has no mapping for use of value range outside of dimension. • Willing to adopt AP-214 usage in those cases. • AP-214 has mappings for value range but no vendor implementation within dimension. • There are vendor implementations of value range outside of dimension

  14. Value Range AP-214 Mapping For significant digits, a complex instance with qualified rep item is used, which points to a precision qualifier Property definition on product, feature, feature component, action, resource, or anything using a representation precision_qualifier precision_value = 4 representation complex instance of measure_representation_item length_measure_with_unit name = “upper limit” value = 100 mm complex instance of value_range qualified_representation_item name = “length” complex instance of measure_representation_item length_measure_with_unit name = “lower limit” value = 75 mm

  15. Value Range AP-224 Mapping geometry and placement instances Significant digits are related to each value separately using a measure qualification shape_aspect dimensional_size dimensional characteristic representation measure_qualification precision_qualifier precision_value = 4 measure_qualification shape dimension representation complex instance of measure_representation_item length_measure_with_unit name = “upper range” value = 100 mm complex instance of measure_representation_item length_measure_with_unit name = “lower range” value = 75 mm

  16. Value Range - Still In Discussion • Proposed solution is to use • AP-214 value_range AIM mapping outside of dimensions • AP-224 two rep item mapping inside of dimensions • Willingness from AP-224 to use value_range outside of dimensions, and extend ARM to support ranges for normal properties. • AP-214 unsure about using two rep item approach inside of dimensions. • Max Ungerer wants to discuss this with his team. • Continue discussion on value range via email/conf call, once Max has had time to get additional input from his team.

  17. Plus/Minus • AP-224 has implementation of both plus/minus mappings (in dimensions, in feature properties) • AP-214 has mappings for plus minus but no vendor implementation within dimension. • No implementations outside of dimensions • Mappings currently have an error that always requires the use of dimensional_size, even in a location dimension. • Module 1106 and 1050 mappings • 1106 has Plus/Minus for use outside of dimensions • Adopt the qualified rep item mappings • 1050 has Plus/Minus for use inside dimensions • Should have correct mappings, but derived from AP-214, so check to make sure that they do not have the same problem.

  18. Plus/Minus Resolution • Agreement on separate representations for use inside and outside of dimensions. • See following slides for diagrams • AP-214 to correct mappings inside dimension to make proper use of dimensional_size, add new mapping for use outside of dimensions

  19. Plus/Minus Outside of a Dimension (1/2) NOT FOR USE WITH A SIZE DIMENSION OR LOCATION DIMENSION (which are mapped to Part 47 dimensional_size or dimensional_location) All other property definitions on product, feature, feature component, action, resource, or anything using a representation Adds qualified representation item to the complex instance Points to separate qualifiers for upper, lower limits and significant digits representation complex instance of measure_representation_item length_measure_with_unit qualified_representation_item name = “length” value = 100 mm standard_uncertainty measure_name = “upper limit” uncertainty_value = 0.001 standard_uncertainty measure_name = “lower limit” uncertainty_value = - 0.001 This is an example with length, could be used for angles, times, velocities, etc. as supported by the range of things representable by measure_with_unit precision_qualifier precision_value = 4

  20. Plus/Minus Outside of a Dimension (2/2) NOT FOR USE WITH A SIZE DIMENSION OR LOCATION DIMENSION (which are mapped to Part 47 dimensional_size or dimensional_location) All other property definitions on product, feature, feature component, action, resource, or anything using a representation This is current AP-224 representation. AP-214 to add alternate mapping for use outside of dimensions when correcting mapping of plus/minus tolerance to dimensional_* entities representation complex instance of measure_representation_item length_measure_with_unit qualified_representation_item name = “length” value = 100 mm standard_uncertainty measure_name = “upper limit” uncertainty_value = 0.001 standard_uncertainty measure_name = “lower limit” uncertainty_value = - 0.001 precision_qualifier precision_value = 4

  21. Plus/Minus Using Dimension Geometry and location AP-214 current mapping always requires a dimensional_size, even if a location dimension (need to fix mapping) of_shape shape_aspect dimensional_size plus_minus_tolerance dimensional characteristic representation tolerance_value lower_ bound shape dimension representation upper_bound length_measure_with_unit value = 0.001 length_measure_with_unit value = - 0.001 complex instance of measure_representation_item length_measure_with_unit qualified_representation_item value = 100 mm measure_qualification precision_qualifier precision_value = 4 measure_qualification

  22. Limits and Fits • AP-224 need information about implementation. • AP-214 has mappings for limits and fits but no vendor implementation within dimension. • No implementations outside of dimensions • Mappings currently have an error that always requires the use of dimensional_size, even in a location dimension. • AP-238 has requirement for use outside of dimension (as a property) • Has developed mappings based on qualified rep item that follow the AP-224 plus / minus pattern. • Agreed to follow resolution adopted for plus minus

  23. Limits and Fits Outside of a Dimension NOT FOR USE WITH A SIZE DIMENSION OR LOCATION DIMENSION (which are mapped to Part 47 dimensional_size or dimensional_location) All other property definitions on product, feature, feature component, action, resource, or anything using a representation Follows the pattern established by the Plus/Minus mapping with qualifiers for each fit descriptor representation qualitative_uncertainty measure_name = “form variance” uncertainty_value = “A” complex instance of measure_representation_item length_measure_with_unit qualified_representation_item name = “diameter” value = 100 mm qualitative_uncertainty measure_name = “zone variance” uncertainty_value = “H” qualitative_uncertainty measure_name = “grade” uncertainty_value = “IT01” Adds qualified representation item to the complex instance Uses qualitative_uncertainty for descriptors precision_qualifier precision_value = 4

  24. Limits and Fits Using Dimension Geometry and location AP-214 requires mapping fix already noted in plus/minus slide of_shape shape_aspect dimensional_size plus_minus_tolerance dimensional characteristic representation limits_and_fits form_variance = “A” zone_variance = “H” grade = “IT01” shape dimension representation complex instance of measure_representation_item length_measure_with_unit qualified_representation_item value = 100 mm precision_qualifier precision_value = 4

  25. Current Dimension Types • Available Dimensions in AP-214 and AP-224 • location dimension • distance_along_curve/curved_distance (224,214,202) • angular_dimension/angular_location (224,214,202) • location_dimension/linear_distance (224,214,202) • size dimension • radial_dimension (224) • diameter_dimension (224) • curved_dimension (224) • angular_size_dimension (224,214) • thickness (214) • general_size (214) • Module 1050 currently has only the AP-214 ones. 202

  26. Discussion • size dimension • Comment to add size dimensions for each drawing symbol not attractive to cax-if vendors • radial, diameter, curved currently under general_size in 214 • width, height may also be general_size in 214 • thickness (214) • Requirements coming from tube/piping thickness, coatings • AP-224 agrees to harmonize with any explicit tolerance types, but will not adopt a “generic” size tolerance. • general_size (214) (NOT radius, diameter, dimension) • Change to “externally_defined_size” with document reference

  27. Suggestion ENTITY externally_defined_size_dimension  SUBTYPE OF (Size_dimension);  external_source_id : STRING;  external_source : assigned_document_select;  used_path : OPTIONAL Measurement_path;END_ENTITY; Aside from renaming in the ARM, upward compatible with existing general_size definition In ARM, AP-214 and modules may do as a separate document_assignment + rule to require it. In ARM, AP-224 may do as above. In AIMs, will be mapped as document assignment

  28. Dimension Type Resolutions • Change general_size to externally defined size as in previous slide. • Upward compatible change to AP-214, Module 1050 • New addition to AP-224 • Move specific types out from general_size • radius, diameter, curved path become separate ARM objects in AP-214 and module 1050 • May be several others (width? height? length?) • Add missing size dimensions to AP-224 • thickness • Others coming from general_size as above.

  29. Envelope Principle • AP-224 • Mapped as the name of the dimensional characteristic representation • AP-214 • Mapped as classification assignment on plus_minus_tolerance • Module 1050 • Mapped as classification assignment on dimensional_size • See diagram on next slide

  30. Envelope Principle AP-214 group name=“E” description = “dimensioning principle” Geometry and location of_shape shape_aspect classification_role name=“further tolerance requirement” dimensional_size 1050 dimensional characteristic representation applied_classification_assignment shape dimension representation name = “envelope tolerance” AP-224 plus_minus_tolerance tolerance_value lower_ bound upper_bound complex instance of measure_representation_item length_measure_with_unit qualified_representation_item name = “length” value = 100 mm length_measure_with_unit value = 0.001 length_measure_with_unit value = - 0.001

  31. Envelope Resolution • AP-214/Module 1050 • Change to dimensional_characteristic_representation.name approach in the AIM. • AP-214 must relax ARM to allow envelope on any size dimension. Move attribute envelope from value_limitation to size_dimension • AP-224 • Restrict usage of envelope to size only by moving attribute in the ARM to size_dimension

  32. Directed Angular Location • Notion of directed dimension currently supported by linear distance • directed attribute on linear distance dimension • Not by angular location dimension in either AP • No attribute for directed, but examples exist in other standards • Defer until we discuss other issues with angular location

  33. Angular Location Mirroring • There are cases where it is difficult to determine the angle • Need some sort of path or location/orientation to be able to determine the enclosed angle • If orientation is used, one line lies on X axis, other line lies counterclocwise towards Y axis. (right hand rule) • Leave this alone for now • Not a harmonization problem, AP-224/AP-214 • Continue to study, if improvements become clear, handle as SEDS

More Related